It is common for long-running series to feature Call Backs, in which characters make a quick Shout-Out to an event that happened earlier in the series. This provides a nice reference for long term fans to pick up on and helps establish a sense of continuity—after all, the characters should remember the things that they've done in the past.
The inversion of this is a Call Forward, when a character in a prequel makes an offhand comment about something that viewers know will happen in the future, but the character him or herself is unaware of. Usually this takes the form of a derisive statement like "X? That's the Stupidest Thing I've Ever Heard", where X is a major theme in the series. Done well, this can be a good inside joke in the same sense as a Call Back or even provide an explanation for why something happens in the future, but done badly it can seem bizarre that the character would say something like that.
If the predictive statement appears in a work released before the event it predicts, this is Foreshadowing or a "Funny Aneurysm" Moment. If the story is set in the past and the prediction is of a real-life event, then this often overlaps with It Will Never Catch On or This Is Going To Be Huge. Flashback to Catchphrase can be related, especially if it's preceded by "I'm only going say this once..." or "I can't believe I'm saying this, but..."
In Soul Eater Not!, the prequel to Soul Eater, Kim is called the "witch of the girls' dormitory" because she is mean to the other students in the girls' dormitory. It was revealed around chapter 50 of Soul Eater proper that Kim is actually a witch.
The 'old lady' that acts as the DWMA mission receptions makes an appearance in Not!, where she explains she was a student in the EAT class, and even though she's retired she'll be quick to jump to the front lines if the students ever need her. In the main manga she had already done so, joining the fight in the last arc of the series, and had already been killed.
The first chapter of Yu-Gi-Oh! Millennium World is set before the original Yu-Gi-Oh. Sugoroku Muto (Yugi's grandpa) is a skilled gamer that says that if he ever loses a game, he'll trade his suit and fedora for a pair of overalls and a bandanna, and will open a game store. Apparently he lost.
Due to Anachronic Order, the anime version of The Melancholy Of Haruhi Suzumiya has this. Even if watched in chronological order, there are still a few of these, mostly because the light novels the series was adapting were ahead of the anime, so the producers knew exactly what was coming.
Genbu Warriors Hikitsu and Tomite of Fushigi Yuugi Genbu Kaiden made offhand comments indicating how it's impossible to meet The Suzaku Warriors of Fushigi Yuugi since it's most likely they're a couple of hundred years apart.
In the Saint Beast OVAs, young Kira and Maya are searching around the treasury and find the twins of Saint Beast weapons that will eventually be used to brainwash Goh, Shin, Rey, and Gai to betray their friends.
Gundam Unicorn, veritable redtube of Continuity Porn that it is, has a few nods to future Gundam shows, such as Gundam F91 (the transforming tank MS Loto being a prototype of the Guntank R-44, Banagher having a part time job at a company owned by the Ronah family), Hathaway's Flash (the Kshatriya R's Funnel Missiles being a forerunner of a weapon that appears in the novel, and the Gustav Karl mobile suit makes a brief appearance) and even the obscure novel and radio play Gaia Gear which was assumed to be non-canon (both feature a Federation counter-terrorist group called the Manhunters).
Dragon Ball SD, being a full colour remake/parody of the Dragon Ball manga has a number of call forwards to later events in the series.
In the X-Men: First Class oneshot Iceman & Angel, Bobby discusses how totally cool it would be if Warren's wings were made of knives.
The Noob comic is a Broad Strokes adaptation written by the creator of the webseries of the same name. By the time something gets Foreshadowing in the comic, it usually already happened in the webseries and novels, whose timeline is progressing faster.
The penultimate story arc of The Punisher MAX dealt with Frank's difficulty adjusting to civilian life, including a fellow soldier saying he couldn't imagine Castle taking his kids on a family picnic.
In Better Angels, a For Want of a Nail fic about Shane Walsh killing Rick Grimes, Shane notes that a person needs to be bitten to turn into a Walker. Due to Rick's demise, the secret that Dr. Jenner told Rick is never revealed, so Shane nor anyone else in the Atlanta group is initially aware, and Shane shoots Rick's head before he can reanimate as Shane did in canon.
Cadance Of Cloudsdale, being set a few decades before the main series, has quite a few. For example, Cadance mentions that Twilight Sparkle is really dedicated to learning magic, and might make a good student of Celestia'snote That's exactly what happens in the series.
Queen Of All Oni: In one flashback, when Hiruzen posthumously spoke to Tarakudo through his own severed head, Tarakudo found the concept of a floating head fascinating. This implies it inspired his own eventual transformation into a floating head.
The WWE story, One More Time, takes place in 2005. During the story, Molly Holly asks Eddie Guerrero what his family will do if anything happens to him, sarcastically presenting the idea of Eddie's wife, Vickie, getting a job with WWE.
The story also has Molly talking about "this girl named Beth" that she helped get placed in OVW.
The Stalking Zuko Series: a respected Ba Sing Se therapist named Dr. Wang is noted to have a very nice beard that Smellerbee imitates when trying to help Jet talk about his problems. Guess where Sokka got his inspiration for the Wang Fire beard?
Since Turnabout Storm takes place at a set point in the timeline of Ace Attorney, it was bound to bring up moments from later moments in the series, such as Phoenix's future daughter ("Me with children? That'll be the day."), and his get-up in Apollo Justice: Ace Attorney ("What does she think I am, a hobo?").
The World of the Creatures takes place sometime in September of 2012. At one point, The 10th Doctor mentions not being very well versed in watercolors or beekeeping. The 11th Doctor would express an interest in learning these two hobbies in the May 2013 episode, "The Name of the Doctor." In addition, The Ninth Doctor mentions wanting to learn how to fly a biplane. Eleven would finally get around to scheduling a lesson, but he was side tracked by the events of "The Impossible Astronaut"
Scooby-Doo! The Mystery Begins is full of these, the least of which being Velma referencing the first ever episode of Scooby Doo, Where Are You? at the end by suggesting they check out some "strange happenings at the museum."
An example would be '70s!Erik's "Imagine if [your claws] were metal" remark to Logan.
When '70s!Erik goes to retrieve his helmet from the Pentagon, he's shown wearing a fedora and dark suit ensemble very similar to Magneto's civilian appearance in the first X-Men film. He also uses small metal balls, like in X2.
When Logan passes through a metal detector, he's briefly surprised that it doesn't go off. Doubles as a Call Back to the first X-Men film.
Used for Dramatic Irony when Trask says to Stryker that by the time the upcoming human-mutant war arrives, his son will be old enough to fight in it. Stryker's son does become a victim of this war, as he's a mutant and his own father turns on him.
In his New Era Speech, '70s!Magneto mentions "a Brotherhood of our kind."
In the finale, Beast uses a handful of hypodermic needles of his serum to supress his mutant genes, in order to hide from a Sentinel's sensors. In the finale of X3: The Last Stand, Beast uses a handful of hypodermic needles of a different serum to suppress Magneto's mutant genes and gain the upper hand on Alcatraz.
While watching an orc gladiator called Thrall fight in Durnholde Keep, the titular character in Arthas: Rise of the Lich King worries that if the orc escapes, he could teach his considerable tactical and strategical skills to other orcs, triggering the orcs' resurgence as a major faction in Azeroth. Another Warcraft Expanded Universe novel, Lord of the Clans, features Thrall doing exactly that.
The two books are written by the same woman, Christie Golden, and the reference is a rare not-very-disruptive tidbit of Author Appeal.
The Provost's Dog series by Tamora Pierce is set two hundred years before current [[Literature/Tortall]] continuity. The second book in particular, Bloodhound, is rife with references to locations, nations and noble families that feature heavily in the other Tortall books. One notable example is Sir Lionel of Trebond, the ancestor of the heroine of the first ever Tortall series, Song of the Lioness. Luckily she doesn't inherit his personality, though.
The idea for "The Tower of the Elephant" seems to have occurred to Howard while he was completing revisions on "The Phoenix on the Sword." The final draft of "The Phoenix on the Sword" contains the phrase "Zamora with its... towers of spider-haunted mystery," mirroring a scene that would appear in "The Tower of the Elephant."
Warhammer 40,000 has the Horus Heresy series of novels, which details the titular event about 10,000 years before the "current day" of the game that permanently crippled the Imperium, and lead to the current state of the setting. All throughout the series, this trope occurs many, many times.
There are several of these in the Diogenes Club series, which wasn't written in chronological order.
In "Sorcerer, Conjurer, Wizard, Witch", set in The Thirties, Charles Beauregard, dealing with yet another Great Enchanter, wonders vaguely if they "crawl fully grown from filthy water". We don't learn if this is the case for Colonel Zenf, but it certainly is for his successor in The Eighties, Derek Leech, who according to The Quorum emerged from the pollution of the Thames in precisely this manner in 1961 (according to "Cold Snap", immediately after Zenf's death).
"Cold Snap" itself contains multiple calls-forward, since it ties all of Newman's contemporary fantasy/horror novels into the Diogenes Club timeline by way of appearances from significant characters but is set before most of said novels.
In The Serial Murders, Richard Jeperson meets an annoying parapsychologist named Adam Onions who works for an outfit called IΨT ("I-Psi-T", pronounced like "Eyesight"). IΨT first appeared in Jago and Onions features in Swellhead, both of which are set after The Serial Murders but were written earlier.
Remember City of Fallen Angels when Jace sleeps in the Silent City and sees initials scratched onto the wall? Clockwork Prince reveals that those stood for "Jessamine Gray."
In the prequel to The Tripods, there's a scene where the protagonist, Laurie, looks up at the sky and wonders if sometime in the future, other humans will look up at the sky and 'dream of freedom'. This is a callback to a scene in the first book where Will, Henry and Beanpole find themselves looking up at the sky after they arrive in at the mountain resistance base.
In the first Torchwood novel, Another Life, set early in the first season, but published the following year, Ianto hears Owen use the word "cybersex", and briefly panics, before realising it's nothing to do with his secret.
Live Action TV
Angel: A flashback to WWII in the episode "Why We Fight" contained the following dialogue (they were stuck on a submarine at the time):
Angel: I'm not getting trapped at the bottom of the sea!
Spike: And I'm not getting experimented on by the government!
This becomes even more awesome if you've paid attention. Angel was drafted by the then-new Initiative, who does the aforementioned experimenting on Spike in 1999 or 2000 and the experiment is hinted to be based off the Nazi research the US was trying to get off that ship, which Spike torched. Spike also wears the Nazi uniform because he likes the jacket, a call forward to the history of his famous leather duster, which was also taken from the corpse of an enemy. Also, weights are used to sink Angel to the bottom of the sea, much like what his son Conner would do to him almost 60 years later. Spike being forced to rush for cover before sunrise before he gets burned up is a call forward to the running gag of him running through Sunnydale, on fire, to get places during daylight on the parent show, Buffy the Vampire Slayer.
In Spike's first appearance, Giles mentions that he got his nickname by driving railroad spikes through his victims' heads. Three seasons later, "Fool For Love" reveals that, before he became a vampire, Spike was a fop best known for his atrocious poetry; one of his "critics" claims that he'd rather have a railroad spike driven through his head than listen to it. Apparently, he got his wish.
Breaking Bad: Done in one episode, and rather fiendishly. Jane, via flashback: "That was so sweet, I think I just threw up in my mouth a little..." Jane died by asphyxiating on her own vomit
The writers had a lot of fun with Jane. In another episode before her death, Jesse is cooking her breakfast and is disappointed that she wakes up before he can surprise her. Jesse: "You weren't supposed to wake up!" Jane: "Ever, or...?". Only a couple of episodes later - she doesn't.
Doctor Who: In the episode "Flesh and Stone", River Song unwittingly references her own death in her future from last season.
And it happened again in "The Impossible Astronaut." Rather more poignantly this time around.
River Song is prone to these, due to the extremely timey-wimey nature of her time-line. Like how in "The Wedding of River Song", where the Doctor is (apparently) about to die; River says that 'Time can be rewritten', with the Doctor responding "Don't you dare," the same thing she said at her death. And the way that she knocked the Doctor out and hand-cuffed him to take his place in a Heroic Sacrifice was exactly the same thing her mum, Amy did, in "The Eleventh Hour".
Quite a few show up in The Day of The Doctor.
The 10th Doctor says, "I don't wanna go."
At one point, 10 finds 11's fez. And puts it on.
Downton Abbey: Mrs Hughes does a corker when it comes to this trope; it's so bad that millions of fans still smack their hands to their heads when they hear it. "What if there's a flood? What if there's a war?" - that line is in 1913... and we ALL know that 1914 brings said war that she used in her example.
Friends: A flashback has Ross proudly tell his parents that his new girlfriend is really athletic; she's on the lacrosse team and the golf team. Yes, Carol "plays for both teams"...
True, but it's implied that Carol and Susan begin dating while she is still with Ross, so there may have been a period of bisexuality.
Plus Carol kissed Ross when Susan had to work on Valentine's Day.
Friends has loads, especially in their first flashback episode: Phoebe mentions that "cute naked guy" was starting to put on some weight, Ross is excited about Carol befriending "a Susan something" and encourages her to have a "girl's night", Chandler says he doesn't wanna have a roommate handsome enough to relegate him (Chandler) as "the funny one", Monica runs into Rachel and then bets she's never gonna see her again, the gang (then consisting of four of the six main characters) comment on how the bar is closing and wonder where are they going to hang out...
In "The One With All The Thanksgivings", there's a flashback where a teenage Monica has a crush on Chandler and makes him som mac'n'cheese for Thanksgiving dinner. Afterward she asks if he liked it, and he somewhat sarcastically remarks, "Yeah, it was great. You should be a chef." Monica giggles and says, "Okay!"
Home Improvement: On one episode, Tim shows the audience the pilot episode of Tool Time to celebrate the show's fifth anniversary. The pilot consisted of a bearded Tim and clean-shaven Al, who also had complete faith in "an expert like Tim" wielding a giant sledgehammer while Al held the stake...
Little House on the Prairie: One episode, set in the late 1800s, has a serious example. A Jewish man tells his son, Percival, that their people have to make sure to keep their culture alive because for centuries people have tried to destroy their people. Percival dismisses this by saying that "People are more educated now. That kind of craziness won't happen again." What makes this even more notable is the fact that Percival is probably the most intelligent and sensible character in the episode, maybe the entire series.
Well, Percival was right in his suspicion that "that kind of craziness" wouldn't happen in America, which is where they are and (presumably) where they're going to stay.
LOST: In the episode "Meet Kevin Johnson," Sayid becomes violently angry at Michael because he is working for Ben. Of course, we learned five episodes earlier that in the future Sayid himself will be working for Ben.
Mad Men: A staple, with respect to Real Life historical events. The unfortunate scheduling of Roger Sterling's daughter's wedding for November 23, 1963 (the day after John F. Kennedy's assassination) is merely the most blatant.
One that stands out as particularly funny to New Yorkers is the time Peggy considers the impending construction of the Second Avenue Line to be a serious plus for buying a new apartment on the Upper East Side in Season 6 (1968). The Second Avenue Line only broke ground in 2007, and is optimistically expected to open in 2016.
Merlin: In an early episode, whilst watching Arthur and Lancelot share a drink together, Merlin jokingly invites Guinevere to play a game of "Who Would You Rather?" She laughs and states that she'll never have to chose between them. Only the audience knows that one day she'll have to do exactly this, and that the entire future of Camelot may rise or fall on her choice.
Murdoch Mysteries: Used to throw these in once in a while in relation to future Real Life events, but the writers are getting pretty heavy-handed in Season 5 to the point where it's happening at least Once per Episode. And they're not being very subtle either. In a recent episode Detective Murdoch and Constable Crabtree are pondering the possible uses of a sonically-activated switch used to execute the Murder of the Weekwhich actually turns out to be an elaborate suicide:
Crabtree: Perhaps one day you could turn lights on and off by clapping your hands.
NCIS: The episode "Baltimore" has flashbacks to how Gibbs and DiNozzo met when DiNozzo was a Baltimore detective. The episode is littered with Call Forwards.
Tony DiNozzo: Be a Navy cop? I'd rather have the plague.
Once Upon a Time: When Snow meets Red for the first time, she's not yet sure she can trust her so she throws out three different aliases- "Frosty," "Margaret," and "Mary." "Mary Margaret" ends up being the name of her counterpart in Storybrooke.
Stargate SG-1: This occurs in a season eight episode, but in this case the reference is to the spin-off series Stargate Atlantis. After the Atlantis team goes through the gate to the Pegasus galaxy, those on Earth have had no contact from them and don't know what they've found on the other side. The audience, having watched the other series, does know: they're in the Lost City, which is actually a city-sized spaceship that until recently was at the bottom of an ocean. However, in response to the assumption that the Atlantis team found the Lost City, Dr. Novak states, "As far as we know, the Atlantis team found another outpost like the one in Antarctica. Could be on a moon, or at the bottom of some deep, dark ocean."
In season one, Henry VIII says to Anne Boleyn, "Your neck. I love your neck." Everyone who knows the history - or Googles Anne Boleyn - knows that in season two he'll be paying a French swordsman to sever that neck.
On meeting Catherine Howard, Henry asks her if she can write. She tells him "enough to write a letter". It is her love letter to Culpepper that eventually gets her killed.
Lupe Fiasco's The Die (A prequel to The Cool) combines this with Continuity Nod— Michael Young History's unnamed friend says "And if them niggas do kill you in the next few minutes, just remember my nigga, it's a heaven for a G," a reference to "The Cool" (Michael Young History)'s line "Hustler for death, no Heaven for a gangster" in the first CD.
Wicked has some straight mythology gags like Elphaba's line "I'll be so happy I could melt," but also a less comedic instance: her vision of "a celebration throughout Oz that's all to do with me."
Nessarose: What's in the punch?
Boq: Lemons and melons and pears-
Nessarose: Oh my.
Peter and the Starcatcher (a prequel to Peter Pan) has a gag with the boys, when they're lost:
Boys: We're lost!
Molly:(scolding them for their outburst) Boys!
Boys: We're lost!
Anastasia in Shadow Hearts: Covenant notes that there might be trouble if her parents don't improve their relationship with their people. The Anastasia in question is Princess Anastasia Romanova. Covenant takes place in 1915. The only saving grace is that history in the Shadow Hearts universe is vastly different from ours, giving her at least a chance at not getting put against the wall in 1917...
Considering the Anastasia of Shadow Hearts is someone who's gone up against Eldritch Abominations and survived (even bullying one into submission in a Bonus Dungeon) it's tough to see her going out like that.
Fire Emblem: Blazing Blade is a prequel to the previous game, Fire Emblem: Binding Blade, and feature a few foreshadowing moments. Since Blazing Blade was the first game to be released in the west, while Binding Bladewas never released, western players who weren't researching the previous game were a little confused. One major example is that Prince Zephiel, a character the heroes must protect in Blazing Blade, grows up to become the antagonist of Binding Blade.
Another big example is the appearance of Sophia near the end of Blazing Blade; without knowing that she's a major character in Binding Blade and important to the story, western players generally take her for a random cute girl that gives the hero an item after some mysterious dialog.
Another one is the appearance of the Manakete Fae in chapter 22. She's in the NPC house, and Hawkeye says her name if he goes in there.
Final Fantasy XII's Bestiary gives a brief mention of the beginnings of Final Fantasy Tactics's dominant Church of Glabados and its false prophet/demonic founder, Saint Ajora. This mention causes a bit of a translation plot hole, as Ajora is a woman in the Japanese version and a man in English. FFT itself had a bit of trouble with Ajora's gender as well.
Other plot holes exist here as well. FFXII takes place too far in the past for Ajora to have existed yet, the 13 Espers have not yet become the 12 (+1) Lucavi that Ajora used to cause the events she would eventually be worshipped for....
In Devil May Cry 3, Vergil acquires the Beowulf gauntlets and pulls off some rather... impressive martial arts. The game is a prequel to the first. In the first game, after the first Nelo Angelo fight, the boss drops his sword and gets the drop on Dante with his bare hands. Nelo Angelo is actually Vergil.
Also from episode 204: when the past Sam and Max (from episode 102) confront their present selves:
Past Sam: Max and I need to get to the Moon. How do we get there?
Present Sam: Why don't you just drive there? (as they do in episode 106)
Past Sam: You can't just drive to the Moon, bonehead.
Past Max: Sheesh, Sam... our future selves have no respect for plausibility.
In the end of the second Mega Man (Classic) arcade game, Wily reveals that he's working on his ultimate robot, while Bass just snarks that it's girly-looking and will be a loser like all of Wily's other non-Bass robots. The player can, naturally, see Zero's silhouette.
It is no secret that Mega Man (Classic)'s storyline eventually leads into Mega Man X down the road. It's also no secret that in X, a virus is causing reploids to go turn into Mavericks. Cue Mega Man 10's storyline...
After showing off his skills in car combat, a character in Interstate '76 (set in The Seventies) says "Damn, I'm so good, they should name a car after me." His name? Taurus.
In Day Of The Tentacle, Hoagie gets stuck two centuries in the past and, in an attempt to get back to his own time, aids Ben Franklin in the discovery of electric current. In return, Franklin promises to name one of his inventions after him.
Being the source of one of the page quotes, Quest for Glory has a couple of such Call Forwards. In Quest for Glory II, two of the Magic User's potential sponsors shown are a completely black portrait (identified as the "Dark Master"), and Erana (when chosen, the Wizards say that she hasn't answered their summons for some time and asks you to choose again). Quest for Glory IV reveals both the identity of the Dark Master, and what exactly happened to Erana.
Taken a step further in the fan remake; if you insist upon having the Dark Master as your mentor, you get a Non-Standard Game Over where the Wizards get so incensed that they teleport you to Mordavia, the setting of QFG4, and your Have a Nice Death message mentions that you aren't strong enough to survive there.
A now-removed quest-chain in World of Warcraft has a character in Stormwind sarcastically utter the phrase "Next you're going to tell me that Deathwing is still alive and attacking the city." Guess what happened when the Cataclysm expansion was released...
Syndicate's reboot has quite a few. Amongst these are the co-op missions taking place in areas the original games used. The Western Europe map shown in the demo is broadly similar to the original's in having to kill a Colonel, although resistance is much stiffer here.
In the VGA remake of Space Quest, the Time Pod from Space Quest IV lands as you leave Ulence Flats.
Metroid: Other M is a prequel to Fusion. Adam's initial, human form is seen here, as well as Nightmare. It also explains how Ridley ended up as a frozen husk on the BSL in Fusion- Ridley was actually Killed Off For Real in Super Metroid, and the Federation accidentally cloned him. This clone was sucked dry by a Metroid Queen. The husk and Nightmare's body are missing in the Playable Epilogue, most likely being moved to the BSL.
JoJo's Bizarre Adventure: Heritage for the Future: Polnareff, surprisingly, has a few references to Part 5 in him. One super has a Stand Arrow fly out of nowhere and turn Silver Chariot into its Requiem form, putting the opponent to sleep while Polnareff remarks that he can "feel fate within the bow and arrow." (Although Polnareff's still alive this time and the Stand reverts to its previous form afterward.) Furthermore, one of his win vocals translates to him telling the opponent (and the player) that they'll "meet again in the future, in Italy." If you want to be technical, the Arrow could also reference Part 4, where it debuts.
In Chapter 3 of Gunnerkrigg Court, Antimony defends her friend Kat from a bully by Judo-flipping him. One of the teachers, Mr. Eglamore, tells Annie that was against the rules, and then he compliments her throw and tells her that it was noble to stand up for her friend. In Chapter 22, a Whole Episode Flashback shows the young Eglamore getting into a fight in defense of his friends, and receiving a similar warning and compliment from Mr. Thorn.
Since it's set as a prequel to Metal Gear Solid, The Last Days of Foxhound has these a few times. Vulcan Raven even does it in character, since he can see a limited amount of the future, and teases Ocelot on whether or not his hand will get chopped off.
A common source of humor in Darths & Droids, as it is an alternate take on the Star Wars universe; for instance, when Anakin and Chancellor Palpatine have just fallen down an elevator shaft, the Chancellor quips, "This is fun. Perhaps I'll install a huge bottomless pit in my quarters for no apparent reason." Considering how the Canon Palpatine meets his end...
Commentary for El Goonish Shive strips is sometimes added after the original comic is posted. The commentary for the earliest strips (except for the first couple ones) has been added about 12 years after the fact. This has led to at least a couple of Call Forwards:
The commentary of this strip from February of 2002 is in reference to the this strip from October 2002.
One episode of The Simpsons features a flashback to Grampa's time in World War II. When Burns suggests stealing some Nazi paintings, Grampa rationalizes it by saying he needs to put away some money for retirement, after all he'd hate to be put in one of those homes...
In the flashback episode "I Married Marge", after Homer is first hired by Mr. Burns to work at the power plant, Burns comments to Smithers: "Simpson, eh? I'll remember that name."
"Oh Brother, Where Art Thou?" had Homer introduce his children to his long-lost half-brother Herbert. Herbert then discreetly asked Homer if they were all born in wedlock, to which he replies "Yeah, though the boy was a close call." Fast forward to the episode "I Married Marge" where Homer and Marge got married, because they found out that Marge was pregnant with Bart.
The Teen Titans episode "Go!" is practically made up of these. Notable ones include Cyborg saying "I'm only gonna say this once—Booya!" and the team stopping by an island (that of course will eventually house their headquarters) and Cyborg comments that "somebody should build a house out here."
In the Family Guy episode where Peter tells Death how he is devoted to Lois, Quagmire mentions how he hopes Peter will find her again. Peter responds that he hopes Quagmire lives next door to him someday.
An American Tail: The Treasure of Manhattan Island possibly does this with what Fievel says at the beginning:
Fievel: I dreamed that we moved out West where I became a famous gunslinger! Tanya: Yeah, like that would ever happen. Fievel: It seemed real to me!
In the near end of "Code Lyoko" pre-sequel, Odd remarks that "Sissi is going to give them a lot of grief."